Dunham. Qc, Canada; Verger Ivan Duchesne Inc., 1 1 8 

 oh. Sous-Bois, Mont St-Gregoire, Qc, Canada ) in 1997 

 using three trees per sites/replicates. Several 

 commercially grown cultivars (Gala, Spartan, 

 Mcintosh, Lobo) were also grafted onto these 

 rootstocks to assess graft compatibility. During the 

 multiplication and evaluation of the rootstocks, we 

 discovered a clone of 0.3 (0.3A) to be different from 

 original 0.3 developed earlier by Spangelo et. al. 

 (1974). 0.3A appears to produce wider branch angle 

 and have a better rooting efficiency in stool beds 

 compared to the original 0.3. This rootstock (0.3A) 

 was also tested along with advanced SJM rootstocks 

 in all sites. M.27 was planted only at one commercial 

 site due to the insufficient number rootstocks. 



Results & Discussion 



The majority of the superior rootstocks came from 

 R.5 X M.26 crosses, and only one (75-13-065) came 

 from R5 x B57490. The superior rootstocks showed 



no incompatibilit]. with tested commercial scion 

 culti\ ars. All rootstcucks produced trees that were dwarf 

 or semi-dwarf and were easier to propagate and 

 numencally more efficient than trees on M.26 (Table 



2). 



Generally the trees were more vigorous in Dunham 

 (Table 3) than in Mont St-Gregoire (Table 2) based on 

 the trunk circumference. SJP84-5230. M.9, and M.27 

 were the least \ igorous rootstocks in Dunham (Table 

 3) and Mont St-Gregoire (Table 2); how ever, there was 

 not a significant difference between M.2'', SJP84-5230. 

 SJP8--5231, and M.9 in Mont St-Gregoire. MM.lll 

 was the most vigonous at both sites. 



S.iP84-5218 and SJP84-5217 were the most 

 precocious rooistocks at both sites. M.Mlll was the 

 least precocious. In Dunham, SJP84-5 1 98, SJP84-5 1 89, 

 SJP84-5162, and SJIP84-5217 had higher cumulative 

 yield than did .M.26, SJP84-523 1 , MM. ill, M.9, and 

 SJP84-5230 (Table 3). In Mont St-Gregoire, SJP84- 

 52 1 8. SJP84-52 1 7. SJP84-5 1 74, SJP84-5 1 80, 0.3, and 

 0.3 A had higher aumulative yield than did MM.lll 



16 



Fruit Notes, Volume 68, Spring, Summer. & Fall, 2003 



